Phonograph



Feb. 7, 1939. G Z|MMERMANI 2,146,519

PHONOGRAPH File ug. 31 1935 Patented Feb. 7, 1939 PATENT OFFICEPHONOGRAPH Arthur G. Zimmerman, Westmont, N. 1., assignor to RadioCorporation of America, a corporation of Delaware Application Augustin,1935, Serial No. 38,683"

15 Claims.

This invention relates to phonographs, and more particularly to meansfor insuring a turntable supported disc record from slipping on theturntable during playing thereof.

It is well known that, in order to obtain satisfactory reproduction ofsound from a record, the record must move at uniform speed relative tothe sound translating device. Thus, in the case of a phonographemploying disc records, the turntable and the record supported therebymust rotate at uniform speed with respect to the pickup.

Carson and myself, Serial No. 13,796, we have disclosed a system fordriving the turntable of a phonograph with such uniform speed that anyslight variations which may occur therein produce no noticeableundesirable effects.- However, it occasionally happens that the recordsupported by the turntable slips slightly thereon, and this, of course,results in a noticeable variation in the pitch of the reproduced sound.

The primary object of my present invention is to provide an improveddriving connection between the' record and the turntable whereby theaforementioned dimculty is overcome.-

More specifically, it is an'object of my invention to provide a novelrecord driving mechanism whereby the record will be driven positivelyfrom both its surfaces.

It is a further object of my invention to provide, for conventional-discrecords, an improved record drive whereby a turntable supported recordwill be driven not only from the turntable but from the turntablespindle as well.

Another object of. my invention'is to provide an improved record weightwhich will not only press the record against the turntable, but whichwill have driving engagement with) the turntable spindle and which canbe quickly and easily applied to conventional phonographs.

Still another object of my invention is to provide an improved record.weight as aforesaid which will be simple in construction and highlyefiicient in use.

In accordance with my present invention, I provide a record weight witha bore to fit over the turntable spindle and provide means either withinor in association with said bore whereby the weight may have drivingengagement with the spindle. The record weight is also provided with arecord engaging surface of such nature and so arranged that it will havefrictional connection with the top surface of the record. Thus, therecord is driven by the turntable at its'turn- In the copendingapplication of Benjamin 1t.

table contacting surface and by the spindle driven weight at itsopposite surface. The record engaging surface of the weight may, ifdesired, be so arranged, that a partial vacuum is created between it andthe record, whereby the weight grips the record firmly to assist inrotating it without slipping on the turntable.

The novel features that I consider characteristic of my invention areset forth with particular'ity in the appended claims. However, the'invention itself, together with additional objects and advantagesthereof, will best be understood from the following description of twospecific embodiments thereof, when read in connection with theaccompanying drawing in which Figurev 1 is a view, partly in section, ofone form of my improved record weight,

' Figure 2 is a sectional view taken on the line 2-2 of Figure 1, x

Figure 3 is a detail perspective view of a 'plate for providing drivingconnection between the spindle and the record weight'according to oneform of my invention.

Figure 4 is a fragmentary, detail perspective of the spindle, and

Figure 5 -is a fra entary, sectional detail 'showing a modified form ofmy invention.

Referring more specifically to the drawing, wherein like referencecharacters designate corresponding parts' throughout, there is shown amotorboard l which supports a motor 3 for driving a turntable spindle 5on which is supported a turntable 'l. The turntable has drivingengagement with the spindle 5 through the cross pin 9 which isreceivedby the turntable hub II, and it is provided with the usual felt surface(not shown), on which a record R rests, the felt serving to provide africtional drive between the record and the turntable. The constructionthus far described is more or less conventional and is subject to thedisadvantages heretofore pointed out,

To insure against slipping of the record R on the turntable I, Ipreferably form the protruding end 5aof the spindle 5 of a non-circularshape and cause it to drive a record weight l3 which rests on the recordR. The weight [3 is made of a mass of metal and is provided with acentral bore I 5 for receiving the spindle end 5a when it is placed on arecord, while a driving plate l1, secured to the mass I 3 by the screwsl9 and provided with an aperture 2| of a configuration corresponding tothe shape of the spindle end 5a, serves to provide a driving connectionbetween the spindle 5 and the mass l3. In the particular embodimentillustrated in Figs. 1 to 3, the end 511. is shown square with thecorners to thereof rounded off somewhat to prevent injury to the handsand to the record, the aperture 2i being also square and of a dimensionto snugly fit over the end a.- The spindle end So and the aperture 2|may, obviously, beformed of any other polygonal or other suitable shape(for example, elliptical), it being merely necessary that a positivedriving coupling be effected between the spindle 5 and the driving plate91.

To the bottom of the mass it is afiixed a base 23 having agreaterdiameter than the mass it, -a resilient disc 25 of substantially equaldiameter.

i9 and the plate H and without the use of any cement or other adhesive.By making the driving plate ll concentric with the base Hand of muchsmaller diameter than that of the disc 25, the peripheral portion of thelive rubber disc will be free to readily accommodate itself to anyirregularities in the surface of the record which it engages under thepressure of the mass l3, and a firm gripping action will result. In somecases, as where the base 23 and the disc 25 are dished slightly awayfrom the record R, as shown in Fig. 1, a partial vacuum is created-whenthe weight i3 is pressed against the record, thereby enhancing thegripping action between the disc 25 and the record. In any event, itwill be seen that this provides an additional drive for the record R andthat the record is prevented from slipping on the turntable because itis driven from its lower surface by the turntable itself and from itsupper surface by the weight it.

The form of my invention heretofore described requires that the spindleend 5a and the aperture 2! be specially formed. For conventionalphonoraphs employing the usual cylindrical spindle, the modificationshown in Figure 5 may be used. In this form, the plate H is providedwith a plurality of gripping members, such assprings 2'5,

which extend into the bore in converging relation and which-firmly gripthe spindle 5 to provide the necessary driving connection between thespindle and the weight.

Although I have shown and described several embodiments of my invention,I am fully aware' I claim as my invention:

1'. In a phonograph, the combination of a driving member, a turntablehaving driving engagement therewith, arecord supported on saidturntable, and means resting on said record and hav-' -ing drivingconnection with said member, said j means also having grippingengagement with said recordwhereby said record is adapted to be driven aphonograph, the combination of a driving member, a turntablehavingdriving engageboth by said turntable and by said means,

" ment therewith, a record supported on said turntable,- and a recordweight restingon said record and having driving connection with saidmember,-

said 1 weight having gripping engagement with saidrecord whereby saidrecord is adapted. to be driven both by said turntable and by saidweight.

3. In a phonograph, the combination of a motor driven spindle, aturntable having driving enaieatie 'portion and said weight has a memberprovided with a correspondingly shaped aperture adapted to receive saidnon-circular portion whereby to provide driving connection between saidspindle and said weight.

5. The invention set forth in claim 3 characterized in that the spindlehas a substantially square portion at its upper end and said weight hasa driving plate amxed thereto, said plate having a substantially squareopening therein adapted to receive said square portion 'of the spindlewhereby to provide driving connection between said spindle and saidweight.

6. The invention set forth in claim 3 characterized in that the weighthas a resilient member aflixed thereto for providing gripping engagementwith the. record.

'7. A record weight comprising a mass having a bore therein'extendingfrom its base whereby the weight may be fitted over a phonographspindle, a driving plate secured to said base for providing drivingconnection between said mass and said spindle, and a resilient member onsaid base for engaging a phonograph record threaded on said spindlewhereby to provide gripping engagement between said mass and saidrecord.

8. The invention set forth in claim 7 characterized in that saidresilient member comprises a-disc of live rubber.

9. The invention set forth in claim 7 characterized in that the base ofsaid mass is of greater diameter than the body portion thereof,characterized further in that said driving plate is concentric with saidbase and has a much smaller diameter than the base, and characterizedstill further in that said resilient member comprises a disc of liverubber of a diameter substantially equal to that of said base, saidrubber disc being held against said base solely by'said driving platewhereby the peripheral portion of said rubber disc is free to snuglyengage the record in firm gripping engagement therewith.

10. The invention set forth in claim 7 characterized in that saiddriving plate is provided with a spindle gripping member.

11. The invention set forth in claim 7 characterized in that saiddriving plate is provided with a plurality of resilient spindle grippingelements adapted to cooperate mutually to grip said spindle.

. 12. The invention set forth in claim 7 char? acterized in that saiddriving plate is provided with aplurality of resilient spindle grippingelements extending into said bore in converging relation,

13. Ina phonograph, the combination of a turntable spindle having'an endportion of noncircular shape, and a record weight; said'record weighthaving a central'bore for receiving said end portion and having adriving plate afiixed thereto, and said driving 'plate having anaperture therein of corresponding'shape to receive said 2,140,519 3acterized inthat said spindle end portion issubacterized in that saidspindle end portion is substantially polygonal and said aperture iscorstantially square and said aperture is also square, respondinglysubstantially polygonal, said driving said driving plate being affixedto the base of plate being afllxecl to the base of said weight saidweight with its aperture coaxial with said with its aperturesubstantially coaxial with said bore. 5 base. l ARTHUR G. ZIMMERMAN.

15. The invention set forth in claim 13 char-

